I'd also go with tachyon's suggestion of HTML Tidy, but if you are trying to do this quick and dirty somewhere in the middle of a script, I'd use this regex $text =~ s#<\s*([^>]*)\s*>[\s\n]*<\s*/\s*\1\s*>##ig;
It should remove any empty tags which don't contain any attributes (not just bold tags), so it works on

__DATA__
<i> </ I>
< B ></b>
< em>  < / eM  >
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